Hi;

I'm crafting a setup that makes use of "absolute HDRI" images for light domes, as described in this paper [blog.selfshadow.com].

These domes feature pixels that represent absolute luminance values; to look at them, they simply look "white" because display devices cannot accurately display them. This makes it a bit annoying to both view thumbnails of them and to use them in Houdini, as they blow out the viewport and cannot show meaningful results until rendered (and even then, a camera with exposure compensation must be used).

The paper notes (on page 69) that in practice, it can be nicer to save the HDRI files with more pleasant-to-view pixel values, and calculate an offset that mults the image up at render time to the proper luminance values. Unity says they apply this intensity correction at render time, in the light shader.

I like this trick, I want to do it too!

I'm curious how I might go about doing this in Solaris. One approach I can imagine is having a dome light, then downstream, a Python node that reads the dome light image, looks for the luminance offset value, and sets the intensity of the dome light accordingly. This would still cause viewport blowout, so not ideal though. I'm curious what other approaches (if any) might exist?

Thank you!